I did some of it in TXR Lisp a bunch of years ago. https://www.kylheku.com/cgit/advent/tree/2021 https://www.kylheku.com/cgit/advent/tree/2021 Give it a try.

I did some of it in TXR Lisp a bunch of years ago. https://www.kylheku.com/cgit/advent/tree/2021 https://www.kylheku.com/cgit/advent/tree/2021 Give it a try. The structure and recurring themes in these solutions could be used as a source of ideas for how to get started.